Figure 3

RT-PCR analysis for the PSPPH_2530, PSPPH_2524 and 16S gene expression in bacterial total RNA. A. RT-PCR analysis for the PSPPH_2524 expression: 1) on total RNA from P. syringae pv phaseolicola 1448a cultivated in Hrp-induction medium, 2) on total RNA from P. syringae pv phaseolicola 1448a cultivated in LB medium, 3) on total RNA from P. syringae pv tomato DC3000 cultivated in LB medium (as a negative control). B. RT-PCR analysis for the PSPPH_2530 expression: 1) on total RNA from P. syringae pv phaseolicola 1448a cultivated in Hrp-induction medium, 2) on total RNA from P. syringae pv phaseolicola 1448a cultivated in LB medium, 3) on total RNA from P. syringae pv tomato DC3000 cultivated in LB medium (as a negative control). C. RT-PCR analysis for the 16S rDNA expression (as a positive control): 1) on total RNA from P. syringae pv phaseolicola 1448a cultivated in Hrp-induction medium, 2) on total RNA from P. syringae pv phaseolicola 1448a cultivated in LB medium, 3) on total RNA from P. syringae pv tomato DC3000 cultivated in LB medium. D. Negative control PCR was performed on the total RNA isolates from 1) P. syringae pv phaseolicola 1448a cultivated in Hrp-induction medium 2) P. syringae pv phaseolicola 1448a cultivated in LB medium, 3) P. syringae pv tomato DC3000 cultivated in LB medium, without Reverse Transcriptase assay using the 16S rDNA primers in order to accredit no DNA contamination in the total RNA samples. PCR products were electrophoretically resolved on ethidium bromide (0.5 μg mL^-1)-containing agarose gels (1.5%, w/v). M1: λ DNA digested with PstI, M2: λ DNA digested with EcoRI-HindIII. Even though the total mRNA templates were equal for all PCR samples, the signals in hrp induction medium are very weak, so they have been highlighted by an arrow.